After a long phasing-out, leaded gasoline for cars finally disappeared last year from the face of the earth. But its consequences will be with us for a long time, according to a study published last week in the Proceedings of the National Academy of Sciences.
Lead has been known to be toxic to humans for centuries. But early in the era of the internal-combustion automobile, in the 1920s, an engineer working for General Motors discovered that adding tetraethyl lead (TEL) to fuel was a cheap way of quieting engine knock.
Decades later, a geochemist at Caltech Clair Patterson, raised alarms about the danger of letting large masses of TEL into the atmosphere in this way. By the 1980s most gas was unleaded. But the history raised interesting questions researchers have been studying of late: what were the consequences for people who were children between 1950 and 1981 of the fact that so much lead was being regularly emitted from tailpipes?
In Pill Form:
Scientists from Florida State University and Duke University have found that 90% of children born in the U.S. between 1950 and 1981 had blood-lead levels higher than the CDC safety threshold. They also found significant impact on cognitive development: that showed up as a drop in IQ.